North Korea's announcement that it's completing plans to fire four intermediate-range missiles over Japan to land near the US Pacific island territory of Guam has further heightened tensions with the United States.
North Korea's army will complete the plans in mid-August, when they will be ready for leader Kim Jong Un's order, state-run KCNA news agency reported on Thursday.
The plans call for the missiles to land in the sea just 30-40km from Guam.
North Korea's apparently rapid progress in developing nuclear weapons and missiles capable of reaching the US mainland has fuelled tensions that erupted into a war of words between Washington and Pyongyang this week, unnerving regional powers and global investors.
World stocks fell for a third day, with shares in Seoul slumping to a seven-week low.
The rising tensions between North Korea and the US -- the biggest foreign policy crisis Trump has faced in his six-month-old presidency -- contributed to a weak open for US stocks.
The benchmark S&P 500 stock index dropped 0.75 per cent in the first hour of trade. The index has had just two days so far this year where it has closed with losses of more than 1 per cent.
Experts in South Korea say North Korea's plans ratchet up risks significantly, since Washington is likely to view any missile aimed at its territory as a provocation, even if launched as a test.
North Korea has carried out a series of missile and nuclear bomb tests in defiance of the international community.
North Korea announced the plans following US President Donald Trump's comments on Tuesday that any threats by Pyongyang would be "met with fire and fury like the world has never seen", remarks that KCNA called "a load of nonsense".
As announced by North Korea, which added detail to a plan first unveiled on Wednesday, the planned path of the missiles would cross some of the world's busiest sea and air traffic routes.
While North Korea regularly threatens to destroy the United States and its allies, the report was unusual in its detail. It follows two successful tests of an intercontinental missile by the isolated state in July and a series of other missile tests.
Angered as the US and its allies ignore Chinese calls to calm tensions over North Korea, and distracted by domestic concerns, China is largely sitting out the crisis.